Tucked into a corner of the District between RFK Stadium, Pennsylvania Avenue and the Anacostia River, Congressional Cemetery is an underappreciated gem that houses the remains of members of Congress, society dilettantes and legendary (and notorious) figures throughout American history, including J. Edgar Hoover and John Philip Sousa.

But their final resting place is under threat — from the District’s independently managed but government-owned water and sewage authority’s overzealous bureaucrats and officials. A tax on stormwater runoff risks shuttering the cemetery and a dozen more historic cemeteries and open space sites across the District hard hit by astronomical water bills.

The tab for St. Paul’s Rock Creek Cemetery, where three Supreme Court justices rest, went from $3,500 per year to $200,000 thanks to the fees. The 446-acre National Arboretum pays $400,000 each year.

The culprit is D.C. Water’s Clean Rivers Impervious Area Charge, basically a penalty on properties that the agency deems to be contributing to stormwater runoff into the city’s river system.

It was instituted in 2009 after the federal government mandated the city address water overflow issues. The resulting Clean Rivers Project is a series of tunnels dug to deliver wastewater and sewage to the D.C. treatment plant.

The District is home to two terribly polluted rivers — the Anacostia and the Potomac. Giving polluters an incentive to reduce the amount of potential pollutants that flow into the rivers is a sound concept, but the fact that open areas such as cemeteries are hit hardest demonstrates the flaw in the policy’s design.

The fee does not properly account for the actual runoff caused by the property. For example, the National Arboretum doesn’t use D.C. Water’s storm drains and reuses its wastewater for plants, but it still pays a hefty tab.

And, of course, the District’s roads, which feed directly into storm drains, are exempt from the fee for the cleanup project.

Financing the cost of the $2.6 billion tunnel system on the backs of nonprofits and green spaces is ill-conceived.

Maryland imposed a similar “rain tax” in 2012. My colleagues at the Maryland Public Policy Institute examined how the tax was being unfairly implemented and helped persuade lawmakers to partially repeal the mandatory local tax on impervious surfaces to finance water cleanup. Maryland Gov. Larry Hogan (R) campaigned on its repeal and signed the repeal into law in 2015.

But Maryland localities can still opt to collect a fee — and nine counties and Baltimore City do.

At the very least, the District could follow its northern neighbor Baltimore, which also has serious water contamination issues, by exempting green spaces and allowing nonprofits to apply for hardship exemptions.

But that is not enough because the impervious-area charge is out of control with D.C. Water frequently charging low-income residents and nonprofits such as churches extremely high fees without respect to consumption.

Some of the city’s poorest churches in Ward 8, which survive entirely on donations, report average water bills of more than $50,000 a year based on the assumptions of unelected bureaucrats who arbitrarily impose the impervious-area charge on consumers.

D.C. Water’s bureaucrats are unforgiving and insulting, too, offering minuscule credits to offset the high fees that have grown exponentially of late.

Poor residents especially feel the pinch because the charge has nothing to do with property value, income or ability to pay — just with the assessed area of potential water runoff.

The head of D.C. Water, George Hawkins, simply shrugs when confronted with the rain tax’s unfair application, telling the local media, “Unfortunately someone’s got to pay the bill.”

Well, how about asking the owners of the D.C. United soccer team to chip in more for its $300 million facility, part of which is subsidized by the District? Or cut off the billions in subsidies to wealthy developers.

The federal government should ease its mandate and help to finance the project it required the District to undertake.

In the meantime, D.C. Water should scrap the rain tax on the poor, the dead, the green and the faithful. It is a tunnel too far.

The writer is a visiting fellow at the Maryland Public Policy Institute.